24 



Bi VALVES. DONAX. 



liated and even a spiny appearance, as in the Donax Scor- 

 tum and Pubescens. 



A very prevalent color in this genus is a fine rich 

 purple, or purple rays on a white ground; however, many 

 of the species are of an olive-yellow cast, which not un- 

 frequently inclines to a bright orange : others, again, have 

 a pinkish cast, finely lettered with brown zigzag mark- 

 ings, as is the case in the Donax Scripta, &c. and in some 

 instances the shells have a banded appearance. The 

 interior almost always partakes of the coloring of the ex- 

 terior ; and the margin, which is generally of a high color, 

 is almost invariably crenulate or beset with small conti- 

 guous teeth. Although the species and varieties of this 

 genus are but few, yet these few are thinly scattered over 

 most parts of the globe; however, some coasts (the Eu- 

 ropean in particular) supply a prolusion, but not attended 

 by any great variety : they are mostly found buried in 

 the sand. 



The Indian, Atlantic, American, and Northern seas, 

 have also their share, and the Mediterranean even is not 

 exempt from the general contribution. It is not exactly 

 ascertained that any of this genus are natives of rivers. 



The Donax derives its name, in all probability, from 

 its shape, which resembles the barbed head of a javelirj 

 or dart. 



